Environmental analysis of a small scale marine ORC

The Marine ORC prototype unit is based on a conventional low-temperature subcritical Organic Rankine Cycle and has been designed as a waste heat recovery system for the jacket water of marine diesel auxiliary internal combustion engines (ICEs). The system has a nominal power output of 5 kWe and its working fluid is R134a. In the present work, the key remarks of the life cycle analysis on the experimental test rig, installed in Athens, are presented. The inventory has been assembled using manufacturer’s data combined with assumptions from literature and the analysis of the impacts has been conducted using the ReCiPe 2016 method. Τhe system was evaluated in coupling with the auxiliary ICE and was compared against an ICE that could produce on annual basis equal MWh to the coupled ICE-marine ORC system. In fact, the ICE-marine ORC system enhanced the environmental performance up to 3% on many impact categories, apart from the mineral resources and the marine and terrestrial ecotoxicity which is related to the extended use of copper-based materials. Moreover, the study was expanded by analyzing the contribution of the ORC components in the total impact assessment. In fact, the working fluid has a major impact on the ozone depletion and the global warming categories with a share of 91% and 78%, respectively. In terms of mineral resources scarcity and ecotoxicity, the motors/generators and the heat exchangers of the ORC have the largest contribution, owing to their large metal masses.     «

The Marine ORC prototype unit is based on a conventional low-temperature subcritical Organic Rankine Cycle and has been designed as a waste heat recovery system for the jacket water of marine diesel auxiliary internal combustion engines (ICEs). The system has a nominal power output of 5 kWe and its working fluid is R134a. In the present work, the key remarks of the life cycle analysis on the experimental test rig, installed in Athens, are presented. The inventory has been assembled using manufac...     »